Hi @fxmech, and thanks for your query. I am afraid that the Tobii Core SDK Does not contain a blink detection algorithm builtin so it is up to the developer to create what they believe is an appropriate time counter.
Blinks typically last 300-400 milliseconds, so if you base your own detection function (ie a loop counter when gaze date is receive) around this value it should be sufficient for your needs.
Please let us know if we can be of further assistance.